code: def test_only_red(self, device, dtype):
      height = 5
      width = 4
      num_ray_points = 7
      rgbs = torch.zeros(
          (height, width, num_ray_points, 3), dtype=dtype, device=device
      )
      rgbs[..., 0] = 1
      densities = torch.rand(
          (height, width, num_ray_points, 1), dtype=dtype, device=device
      )
  
      points3d = _create_regular_point_cloud(
          height, width, num_ray_points, device=device, dtype=dtype
      )
  
      irreg_renderer = IrregularRenderer()
      rgbs_rendered = irreg_renderer(rgbs, densities, points3d)
      only_reds = torch.zeros_like(
          rgbs_rendered, dtype=dtype, device=device
      )
      only_reds[..., 0] = 1.0
      assert_close(rgbs_rendered, only_reds)
  
file_path: kornia/test/nerf/test_renderer.py
imports: import math
  import torch
  from kornia.core import Device, Tensor
  from kornia.nerf.volume_renderer import IrregularRenderer, RegularRenderer
  from kornia.testing import assert_close
label_desc: Use image node_id 2 for calling the TestRenderer obj's underlying member method code with example usage: obj.test_only_red(device, dtype) without return types